<template>
	<div class="article-container">
		<!-- 导航栏 -->
		<van-nav-bar class="page-nav-bar" @click-left="$router.back()" left-arrow title="移动头条"></van-nav-bar>
		<!-- /导航栏 -->

		<div class="main-wrap">
			<!-- 加载中 -->
			<div v-if="loading" class="loading-wrap">
				<van-loading color="#3296fa" vertical>加载中</van-loading>
			</div>
			<!-- /加载中 -->

			<!-- 加载完成-文章详情 -->
			<div v-else-if="article.title" class="article-detail">
				<!-- 文章标题 -->
				<h1 class="article-title">{{article.title}}</h1>
				<!-- /文章标题 -->

				<!-- 用户信息 -->
				<van-cell class="user-info" center :border="false">
					<van-image class="avatar" slot="icon" round fit="cover" :src="article.aut_photo" />
					<div slot="title" class="user-name">{{article.aut_name}}</div>
					<div slot="label" class="publish-date">{{article.pubdate | relativeTime}}</div>
					<FollowUser class="follow-btn" :userId="article.aut_id" v-model="article.is_followed"></FollowUser>
				</van-cell>
				<!-- /用户信息 -->

				<!-- 文章内容 -->
				<div ref="articleContent" class="markdown-body article-content" v-html="article.content"></div>
				<van-divider>正文结束</van-divider>
				<!-- 底部区域 -->
				<CommentList :list="commentList" :source="article.art_id"
					@onloadSuccess="totalCommentCount = $event.total_count"></CommentList>
				<div class="article-bottom">
					<van-button @click="isPostShow = true" class="comment-btn" type="default" round size="small">写评论
					</van-button>
					<van-icon name="comment-o" :info="totalCommentCount" color="#777" />
					<CollectArticle v-model="article.is_collected" :articleId="article.art_id"></CollectArticle>
					<LikeArticle v-model="article.like_count" :articleId="article.art_id"></LikeArticle>
				</div>
				<van-popup v-model="isPostShow" position="bottom">
					<CommentPost :target="article.art_id" @postSuccess="onPostSuccess"></CommentPost>
				</van-popup>

			</div>

			<!-- /底部区域 -->
			<!-- /加载完成-文章详情 -->

			<!-- 加载失败：404 -->
			<div v-else-if="errStatus === 404" class="error-wrap">
				<van-icon name="failure" />
				<p class="text">该资源不存在或已删除！</p>
			</div>
			<!-- /加载失败：404 -->

			<!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
			<div v-else class="error-wrap">
				<van-icon name="failure" />
				<p class="text">内容加载失败！</p>
				<van-button @click="loadArticle" class="retry-btn">点击重试</van-button>
			</div>
			<!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
		</div>


	</div>
</template>

<script>
	import {
		getArticleById
	} from '@/api/article.js'
	import {
		ImagePreview
	} from 'vant';

	import FollowUser from '@/components/follow-user'
	import CollectArticle from '@/components/collect-article'
	import LikeArticle from '@/components/like-article'
	import CommentList from './components/comment-list.vue'
	import CommentPost from './components/comment-post.vue'

	export default {
		name: 'Article',
		
		components: {
			FollowUser,
			CollectArticle,
			LikeArticle,
			CommentList,
			CommentPost
		},
		props: {
			articleId: {
				type: [Number, String, Object],
				required: true
			}
		},
		data() {
			return {
				article: {},
				loading: true,
				errStatus: 0,
				totalCommentCount: 0,
				commentList: [],
				isPostShow: false
			}
		},
		created() {
			this.loadArticle()
		},
		methods: {
			async loadArticle() {
				this.loading = true
				try {
					const {
						data: res
					} = await getArticleById(this.articleId)
					this.article = res.data

					setTimeout(() => {
						this.previewImage()
					}, 0)
				} catch (e) {
					if (e.response && e.response.status === 404) {
						this.errStatus = 404
					}
				}
				this.loading = false
			},

			previewImage() {
				const articleContent = this.$refs.articleContent
				const imgs = articleContent.querySelectorAll('img')
				const images = []
				imgs.forEach((img, index) => {
					images.push(img.src)
					img.onclick = () => {
						ImagePreview({
							images,
							startPosition: index
						});
					}
				})
			},

			onPostSuccess(data) {
				this.isPostShow = false
				this.commentList.unshift(data.new_obj)
			}
		}
	}
</script>

<style scoped lang="less">
	@import './markdown.css';

	.article-container {
		.main-wrap {
			position: fixed;
			left: 0;
			right: 0;
			top: 92px;
			bottom: 88px;
			overflow-y: scroll;
			background-color: #fff;
		}

		.article-detail {
			.article-title {
				font-size: 40px;
				padding: 50px 32px;
				margin: 0;
				color: #3a3a3a;
			}

			.user-info {
				padding: 0 32px;

				.avatar {
					width: 70px;
					height: 70px;
					margin-right: 17px;
				}

				.van-cell__label {
					margin-top: 0;
				}

				.user-name {
					font-size: 24px;
					color: #3a3a3a;
				}

				.publish-date {
					font-size: 23px;
					color: #b7b7b7;
				}

				.follow-btn {
					width: 170px;
					height: 58px;
				}
			}

			.article-content {
				padding: 55px 32px;

				/deep/ p {
					text-align: justify;
				}
			}
		}

		.loading-wrap {
			padding: 200px 32px;
			display: flex;
			align-items: center;
			justify-content: center;
			background-color: #fff;
		}

		.error-wrap {
			padding: 200px 32px;
			display: flex;
			flex-direction: column;
			align-items: center;
			justify-content: center;
			background-color: #fff;

			.van-icon {
				font-size: 122px;
				color: #b4b4b4;
			}

			.text {
				font-size: 30px;
				color: #666666;
				margin: 33px 0 46px;
			}

			.retry-btn {
				width: 280px;
				height: 70px;
				line-height: 70px;
				border: 1px solid #c3c3c3;
				font-size: 30px;
				color: #666666;
			}
		}

		.article-bottom {
			position: fixed;
			left: 0;
			right: 0;
			bottom: 0;
			display: flex;
			justify-content: space-around;
			align-items: center;
			box-sizing: border-box;
			height: 88px;
			border-top: 1px solid #d8d8d8;
			background-color: #fff;

			.comment-btn {
				width: 282px;
				height: 46px;
				border: 2px solid #eeeeee;
				font-size: 30px;
				line-height: 46px;
				color: #a7a7a7;
			}

			.van-icon {
				font-size: 40px;

				.van-info {
					font-size: 16px;
					background-color: #e22829;
				}
			}
		}
	}
</style>
